linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v2] KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg()
@ 2023-04-19 10:16 Dan Carpenter
  2023-04-19 10:17 ` Steven Price
                   ` (3 more replies)
  0 siblings, 4 replies; 6+ messages in thread
From: Dan Carpenter @ 2023-04-19 10:16 UTC (permalink / raw)
  To: Andre Przywara
  Cc: Oliver Upton, James Morse, Suzuki K Poulose, Zenghui Yu,
	Catalin Marinas, Will Deacon, Eric Auger, Steven Price,
	linux-arm-kernel, kvmarm, kernel-janitors

The KVM_REG_SIZE() comes from the ioctl and it can be a power of two
between 0-32768 but if it is more than sizeof(long) this will corrupt
memory.

Fixes: 99adb567632b ("KVM: arm/arm64: Add save/restore support for firmware workaround state")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
v2: The original patch was okay but checking for != sizeof(val) is
    stricter and more Obviously Correct[tm].  Return -ENOENT instead of
    -EINVAL in case future ioctls are added which take a different size.

 arch/arm64/kvm/hypercalls.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/kvm/hypercalls.c b/arch/arm64/kvm/hypercalls.c
index 2e16fc7b31bf..7fb4df0456de 100644
--- a/arch/arm64/kvm/hypercalls.c
+++ b/arch/arm64/kvm/hypercalls.c
@@ -544,6 +544,8 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	u64 val;
 	int wa_level;
 
+	if (KVM_REG_SIZE(reg->id) != sizeof(val))
+		return -ENOENT;
 	if (copy_from_user(&val, uaddr, KVM_REG_SIZE(reg->id)))
 		return -EFAULT;
 
-- 
2.39.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2023-04-19 15:25 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-04-19 10:16 [PATCH v2] KVM: arm64: Fix buffer overflow in kvm_arm_set_fw_reg() Dan Carpenter
2023-04-19 10:17 ` Steven Price
2023-04-19 10:21 ` Eric Auger
2023-04-19 11:31 ` Marc Zyngier
2023-04-19 12:06   ` Dan Carpenter
2023-04-19 15:24 ` Oliver Upton

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).